This invention relates generally to a one piece plastic beverage container with a footed base structure; and particularly, a container of this type molded with a reduced amount of plastic material while providing optimized material flow in the formation of each foot. These containers are usually, although not exclusively, made from a polyethylene terephthalate (PET) polyester material using a blow molding process that biaxially orients and sets the molecular structure.
A major difficulty in manufacturing such a container is controlling and minimizing the distortion of material flowing to form the footed base structure that can result from the pressure created under normal molding conditions. Such distortion can lead to poor container stability, such as that created by a “rocker bottom”, where distortion in the formation of the base creates a structure such that the supporting feet cannot simultaneously contact the supporting surface. In this case, the container may be unstable and “rock” when placed on a flat surface. Thus, in the case of a footed base, it is important that one manufactures the contact lower surface of each foot properly and that surface remains properly positioned and angled. The present invention enables the consistent manufacture of such a stable footed container; a container having a substantially oval cross-sectional configuration or a substantially kidney shaped cross-sectional configuration. These cross-sectional configurations are often found in containers used by the liquor beverage industry, containers that industry often refers as a hip or pocket flask.
A continuing need exists from an improved molded plastic container and a base therefore that exhibits outstanding stability and offers the consumer the aesthetic appeal of appearing to be “glasslike” in profile. That is, the container having a profile similar to a previously made glass container. Common molding conditions and the difficulties of flowing PET materials into angularly disposed molds have dictated, until now, that the base structures of PET containers be substantially curved surfaces and therefore, such PET containers have had a decidedly non “glasslike” profile appearance. The present invention provides a PET container with a largely straight-sided base structure with subtle curved surfaces, thereby providing a container having a more “glasslike” profile appearance.